Protecting metal surfaces.



UNrrED STATES PATENT OFFICE.

PnoTEcTINe mE-TAL SURFACES.

Specification of Letters Patent.

Patented Oct. 10, 1905.

Application mea october a, 1904. serial No. 227.643.

To all whom, it may concern:

Be it known that I, FRIEDRICH UTHEMANN, a subject of the King ofPrussia, German Emperor, residing at Heiligenbrunner Weg 6, Langfuhr,near Dantzie, Germany, have inventedcertain new and useful Improvementsin Protecting Metal Surfaces, of which the following is a specification.

The present invention relates to the protection of bodies havingsurfaces containing copper or other corrodible metal-for instance,copper pipes-from the action of sea-Water or other corroding Huid. j

According to the preferred form of the present invention as applied tothe' protection of copper or surfaces containing copper againstcorrosion due to the action of salt water the surface of the metal iscovered at as uniformlyrecurring distances as possible with a moreelectroposltve metal-for example, iron-in such form as to leave spacesbetween the portions of the applied metal. Wire-netting, helically-woundwire, perforated sheets, or other suitable forms of theelectropositive-metal may he used. 'Such metal is brought intoelectrical contact with the surface to be protected. The electrolyticaction taking place on salt water having access to the corrodiblesurface brings about a destruction of the electropositive metal, afirmly-adhering uniform layer of iron oxid being simultaneously formedon the copper or other surface. This deposit is not acted upon by thesalt water-that is to say, it is proof against the latter-so that evenafter the complete consumption of the more electropositive metal ampleprotection is afforded. Copper or other pipes which are used to conductthe salt Water are preferably provided internally with a helically-Woundresilient iron or steelY wire, the wire being of such thickness as toamount to about a one hundred and fiftieth part of the surface of thepipe to be protected. The Wire helix or spring is contracteddiametrically and introduced into the pipe, and when released itselasticity causes it to lie so tightly against the inner wall of thepipe that an ordinary current of water cannot drag the helix with it. Inlong pipes and those having many bends the helices may be introducedfrom both ends. The protective oxid layer 'is deposited even on thoseplaces which are not directly reached by the wire, so that such placesare protected from corrosion. Other corrodible metals which are exposedto corroding fluids may be treated in a similar manner to that in whichthe surfaces containing copper are treated.

In the accompanying drawings, Figure 1 shows a surface of copper-forinstance, a

sheet a-which is covered with netted wires b of iron or steel on thatside which comes in contact with the water. The netting may be fixed tothe sheet in any suitable manner, as by clamping, riveting, orotherwise. Fig. 2 shows a pipe d in longitudinal section` which pipe iscovered on its interior with helicall ywound wire f of iron or steel.

It will be noted that the electropositive material s'hould be applied insuch manner as to leave spaces between its parts through which the watermay reach the surface to be protected, and any form, whether of nettedwires, perforated plates, helices, or otherwise, which permits thisaction is included within the term .network, which I have used in theclaims to designate such form of the electropositive metal.

While I have specifically described my invention in its preferred formas applied to protecting surfaces containing copper from corrosion fromsalt water, it will be understood that I do'not wish to be limitedthereto,

as my invention is susceptible of use with other materials and in otherWays than those thus described.

What I claim is-' 1. The method of protecting a surface containing ametal which is liable to be attacked by a corroding fluid, whichconsists in depositing upon such surface a coating from a moreelectropositive metal by distributing it at intervals over said surface,supportingv it in electrical contact with said surface and permittingsuch uid to act upon such metals.

2. The method of protecting the surface of a tube containing a metalwhich is liable to bel attacked by a uid, which consists in applying ahelical strip of electropositive metal thereto, and permitting suchfluid Ato act upon said metals.

3. The method of protecting a surface containing copper from thecorroding action of salt water, which consists in depositing thereon acoating from iron, by supporting a network of iron in electrical contactwith said surface, and permitting such fluid to act upon said metals.

4. A body for use in contact with a corroding Huid having a surfacecontaining a corrodible metal and having a more electropositive metaldistributed at intervals over said IOO surface and supported inelectrical Contact electropositive material in Contact; with said .IOwith said surface. i interior surface.

5. A tube for use in Contact with a coi'rod- In witness whereof I havehereunto signed ing fluid, having a surface containing a eormy name inthe presence of two subscribing rodible metal and a helical strip ofmore eleewitnesses.

tropositive metal supported upon said surface. I FRIEDRICH U'IHEMANN.

6. A tube for use in conveyinga corroding Witnesses:

iuid having an interior surface containing a ERNST GRUMSKI,

corrodible metal, and a helical strip of more ERIK BLMNER.

